I know we've focused mostly on nonfiction writing thus far, but I know there are a lot of closet fiction writers out there too. For those in the midst of writing their first (or umpteenth) novel or short story, here's a good strategy for assessing the effectiveness of your descriptions:
1. Pick a significant piece of description that lasts at least a few paragraphs and contains no dialogue.
2. Read through the section and tally up the following:
-How many simple sentences?
-How many compound sentences?
-How many similies?
-How many metaphors?
3. Assess your numbers. The objective is to get the quantities of each as even as possible.
Note: Adding similies and metaphors help appeal to your readers' senses. If you're feeling gutsy, you can tally how many times you describe sights, sounds, smells, tastes, and textures.
As an example, I had too many compound sentences, which made it difficult for a reader to discern what was going on. Once I chopped down some sentences and placed periods instead of commas, the writing became infinitely better. By the same token, if there are too many simple sentences, feel free to whip out some commas and make for some sentence variety.
And for sentence compounders like me, don't be afraid to bend some grammatical rules in your fiction. It isn't technial writing, so grammar isn't held by the same restrictions.
-The Writer Librarian